In the conventional field of the semiconductor integrated circuit device, it is known to insert a switch transistor (hereafter referred to as SWTR as well) into a power supply line or a ground line to partially interrupt the power supply. In a circuit having the SWTR inserted therein, a large rush current might be generated to charge a capacitance of a power supply line which has been intercepted when the circuit is returned from a power supply interception state to an operation state. There is a fear that the generated large rush current might produce power supply noise and the noise might exert bad influence upon other circuits in operation.
As a first method for solving this problem, it is proposed to suppress the rush current by dividing the power supply switch into switches and turning on them successively. A delay time for successively turning on power supply switches obtained by the division is controlled by providing capacitors between a power supply within the semiconductor integrated circuit device (hereafter referred to as virtual power supply as well) and control lines for controlling the power supply switches obtained by the division.